Trump Lashes Out at China, Sending Markets Falling

President Trump ordered U.S. companies to look for alternatives to China after Beijing said it would add more tariffs to U.S. imports. Can the U.S. president place demands like this on private companies? WSJ's Gerald F. Seib explains the powers a president is unable to revoke.

President Trump said he “hereby ordered” U.S. companies doing business in China to explore relocating their operations and stiffened tariffs on Chinese imports after Beijing unveiled its own new levies on American goods, the latest twists in a trade war rattling investors and confounding central bankers.

Mr. Trump tweeted late Friday afternoon he would raise the tariff rate on existing and planned tariffs by 5 percentage points. Tariffs already in place on about $250 billion of Chinese goods will rise to 30% Oct. 1. Tariffs...